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bulletin of The bureau of fisheries. 
2002 B. The amoimt of thyroid tissue surrounding the vessels is very scarce. Vesicles small, epithelium flattened, filled with 
stainable colloid. Normal thyroid. 
2003 A. Alveoli small and lined with high columnar epithelium, deeply staining nuclei. Colloid absent. Follicles few in 
number and poorly staining. Occasional groups of vesicles of normal appearance. Beginning invasion of areolar tissue. Dense 
connective tissue structure. Growth into bone cavities. Definite alveolo-tubular type beginning carcinoma. 
2004 A, B, C. Space about vessels rather well filled with small-sized vesicles relatively uniform in size. Epithelium is flat, 
tened. Vesicles are filled with stainable colloid. In one small area close to a large vessel area half dozen follicles in which the 
colloid is small in amount, the epithelium cubical. Normal thyroid. 
2005 A. This is evidently one of the tumor fish introduced into this experiment. Targe amoimt of thyroid tissue. Great 
variability in the size of the follicles. Large regular shaped follicles lined with flattened epithelium and filled with stainable colloid. 
Large numbers of small follicles with cubical or flattened epithelium. Varying amount of colloid. Large amount of hyaline con- 
nective tissue stroma. Obviously a tumor which has undergone regression. Tumor tissue fills the entire space around the vessel, 
penetrates to the floor of the mouth, and into the bone cavities. It has previously invaded and destroyed large areas of muscle. 
Contains numerous nematode tubercles, in which no worms are to be found. Spontaneous recovery. See further under that 
heading. 
2005 B. Very few follicles included in this section. Flattened epithelium filled with stainable colloid. Typical vesicles. 
Normal. 
2005 C. Evidently tumor fish introduced into this experiment with spontaneous recovery like 2005 A. Contains two nema- 
tode tubercles, in one of which remnants of a worm can be seen. 
2006 A, B. Thyroid consists of typical vesicles with flattened epithelium filled with stainable colloid. Normal. 
2007 A. Space aroimd the large vessels contains scattered follicles filled with stainable colloid, lined for the most part with 
flattened epithelium. There is marked hyperemia, marked engorgement of the vessels between the follicles, and evidence of 
small extravasation about the follicles. A few follicles are lined with cubical epithelium. Hyperemia of the thyroid, possibly 
beginning hyperplasia. 
2007 B. Tissue badly preserved, evidently overheated in embedding. Shows section of media of aorta around which are 
area-s of closely packed large follicles, lined with cubical epthelium. No colloid. Beginning hyperplasia. 
2008 A, B. Small follicles lined with flattened epithelium, filled with stainable colloid. Normal. 
2008 C. Thyroid tissue in this fish consists of rather compact masses in the region of the large vessels. The epithelium of 
some follicles is slightly cubical. Follicles are filled with stainable colloid. Some evidence of hyperemia in the vessels between 
the follicles. Slight hyperemia of the thyroid. Probably normal. 
2009 A, B. Follicles oval and spherical, lined with flattened epithelium, filled with stainable colloid. Normal. 
2010 B. Vesicles lined with flattened epithelium, filled with stainable colloid. Normal. Aroimd the large vessels the thyroid 
follicles are closely packed; the colloid is reduced in amount but stains deeply. Epithelium is small, cubical. Probably normal. 
Thyroid tissue greatly increased in amount but of normal appearance. 
2010 C. Spherical and oval follicles lined with flattened epithelium filled with stainable colloid. Normal. 
2011 A. Follicles lined with flattened epithelium, filled with stainable colloid. Between the follicles hyperemia of the ves- 
sels. Some evidence of extravasation. Hyperemia of the thyroid. Probably normal. 
2011 B, C. Spherical and oval follicles lined with flattened epithelium, filled with stainable colloid. Normal. 
2015 B. Closely packed follicles of irregular shape with almost complete absence of colloid. Follicles lined with cubical 
epithelium. Small groups of detached follicles lying outside the closely packed area lined with flattened epithelium and filled 
with stainable colloid. First evidences of hyperplasia. Beginning simple hyperplasia. 
2015 C. Between the second and third gill arches the space is filled with loosely arranged follicles, many of which contain 
stainable colloid and are lined with slightly cubical epithelium. Between the follicles, marked hyperemia and engorgement of 
the vessels. Away from this mass in this area of slightly altered thyroid one finds isolated typical normal follicles with deeply 
staining colloid and flattened epithelium. Again, about the aorta above and below it, one finds one or two aggregates of follicles 
with slightly cubical epithelium and evidences of hyperemia. The remainder of the thyroid tissue about the large vessels strictly 
normal. Hyperemia of the thyroid, possibly beginning hyperplasia. Unusual amount of thyroid tissue. 
2098 A. Tumor. Typical alveolo-solid carcinoma for the most part, with areas of papillary formation. Infiltration of muscle, 
bone, and cartilage. Infiltration of wall of vein. Papillary adenoi-carcinoma infiltrating muscle bone and cartilage. Hyaline 
degeneration of the wall of the media of the aorta. (Fig. 90.) 
209S B. Beginning adeno-carcinoma of tubulo-alveolar type. Infiltration of areolar tissue, dense connective tissue structures, 
periosteum of bone and muscle. 
2099 A. Examination of this section shows an unusual amount of thyroid tissue about the large vessels, small follicles lined 
with flattened epithelium, some of them containing stainable colloid, others poorly stained colloid, many of them empty, pushed 
in flattened strands between the dense connective tissue structures, spreading well forward into the areolar tissue and in the 
adjacent bone cavities. (Fig. 91.) Great increase in the amount of thyroid tissue. Only one or two large follicles filled with 
stainable colloid. Immediately adjacent to the large vessels a few follicles with high cubical epithelium and no colloid. The 
whole specimen indicates the previous existence of well-developed hyperplasia followed by regression. 
2099 B, C. Presents the same histological characteristics. Increased amount of thyroid tissue. Many isolated groups 
widely distant from the large vessels. About the large vessels are many tortuous elongated and branching alveoli of tubular 
type, lined with flattened epithelium, free from colloid. (Fig. 92, under “Spontaneous Recovery.”) Colloid almost entirely 
absent. 
